Infrastructures
Superconductivity laboratory at ALBA Synchrotron facilities
SUMAN group has also a dedicated space at ALBA Synchrotron, within a lab focused to boost the energetic transition (Battery Lab) and fully equipped for the research in the field of High Temperature Superconductivity (HTS). In particular, the lab enables chemical synthesis, solution deposition and thermal processing at low temperature for pyrolysis and at high temperature for growth of functional oxides and high temperature superconductors. It possesses chemical lab equipment such as Fume hoods, balances, heating plates, ultrasonic baths, spin coating, optical microscope, tubular furnaces, and a dedicated furnace for in-situ XRD growth at ultrahigh speeds.
Funded by PTI+TransEner CSIC programme (TRE2102002) for Spanish NGEU
The part of the lab centered on superconductivity possess the necessary equipment to grow HTS films and coated conductors using a Chemical Solution Deposition (CSD) methodology. At present, it is devoted to the new high throughput, high performance and low cost “Transient Liquid Assisted Growth, TLAG” process invented by the SUMAN group.
Solution synthesis: Metalorganic solutions can be synthesized in the chemical hoods starting from metalorganic precursor powers. Chemical hoods, balance, glassware, ultrasonic bath, heating plates, solvents and acid cabinets are available.
Deposition and low temperature pyrolysis: Chemical solutions can be deposited on a substrate by spin coating (SMA AC 6000) and organic matter can be eliminated afterwards (if required) in tubular furnace with controlled atmosphere (Ar, air, N2). The resulting layers can be observed by optical microscopy (DM 1750 M from Leica)
Growth of functional oxide films and high temperature superconductors: The lab is equipped with a tubular furnace (Microtest) that reaches 1100ºC and is capable of performing both fast heating ramps and fast jumps in pressure. The high rate heating ramp (T route) can be achieved due to a linear motor on top of which the oven is mounted. Therefore, the heating rate is not limited by the capability of the oven to be heated, but instead is controlled by how fast the sample is introduced inside an already heated furnace. Heating ramps < 1 ºC/s can be reached. On the other hand, the fast pressure jumps (P route) are accomplished connecting the tubular furnace to the same pressure control system used for in-situ 2D X-Ray diffraction-TLAG experiments (see details in the next infrastructure description). Pressure jumps from 10-2 mbar up to to 1 bar can be reached in a controlled time varying from 0.4 s to tens of minutes depending on the pressure range and settings in a controlled atmosphere of N2/O2.
“La PTI+ TRANSENER comienza los experimentos para el desarrollo de un banco de ensayos en el sincrotrón Alba”, PTI+TRANSENERCSIC webpage, 07/03/2022
In situ growth system for 2D X-Ray diffraction analysis and complementary techniques
A unique set-up with two separate pressure circuits and a hot stage enables to control the total pressure, the partial pressure of oxygen, the flow rate, the velocity of the “jump” of pressure, the temperature of growth and the heating rate while monitoring the gas evolution by Mass Spectrometry and resistance of the sample. All the different set ups are time synchronized and located in a movable rack that can be moved to any synchrotron beamline.
The system has been implemented at the NCD-SWEET beamline of ALBA Synchrotron
The XRD-TLAG system, placed on a movable rack, is composed of an Anton Paar DS1100 hot stage, where a sample is placed. The hot stage is able to heat up to 1100 ºC in a maximum heating rate of 300ºC/min. The reaction volume is sealed by an X-Ray transparent graphite dome and connected to two separate vacuum/gas lines by a series of electro-valves. Additionally, one of the vacuum/gas lines is connected in series to a MOVE controller, which gives a possibility of regulating the aperture of this vacuum/gas line from 0 to 100 % and thus control the rate of the pressure increase inside the reaction compartment.
The two gas/vacuum lines enable to be operated at different pressures. One is connected to a rotary pump and the other to a turbomolecular pump with its supporting rotary vane pump. Pressures down to 10-2 mbar and up to 1 bar can be set through mass flow controllers that enable different mixers of N2/O2. A mass spectrometer attached on top of another turbo pump with its supporting rotary vane pump allows to monitor the sample gas environment and the products of reactions happening inside the hot stage. A system of electro-valves and the MOVE control-valve enables to control the switch between the two circuit which translates into a pressure jump in the hot stage which can be reach in a range of time between 0.4 s and tens of minutes depending on the settings and range of pressures. Additionally, two electrical connections arrive to the sample space to measure the electrical conductivity of the sample during the growth process with a Keithley 2450. All the system is computer controlled, time synchronized and integrated in the internal platform network of ALBA.